As a vehicle control system of this kind, it is proposed in Japanese Patent Publication No. 2005-51886, for example, that a torque to be applied by an electric motor to vehicle driving wheels is set, based on a value which is calculated by multiplying a counterbalancing torque to a force of gravitation in a vehicle backward direction by a reflection ratio, or based on a required torque corresponding to an acceleration pedal stroke operated by a vehicle driver, whichever is larger. The reflection ratio is set to become larger, as a rotational speed of the electric motor in a reverse direction is higher. According to such a vehicle control system, the torque generated at the electric motor is increased, when the vehicle driver stops its braking operation (brake-off) in the case that the vehicle is on au uphill slope, and when the vehicle is about to move in the backward direction.
According to the above vehicle control system, however, since the torque applied to the driving wheels shortly after the brake-off is smaller than the force of gravitation in the vehicle backward direction, the vehicle may be moved in the backward direction. In this situation, when the acceleration pedal is operated by the vehicle driver, the torque corresponding to such acceleration pedal stroke is applied to the driving wheels. In the case that the above torque is excessively large, the driving wheels may slip against a road surface. In particular, when the road surface is frozen, the vehicle may be largely moved in the backward direction due to such a vehicle slip. Furthermore, when the slip occurs, the ice will be molten to thereby decrease coefficient of friction between the driving wheels and the road surface. It may happen that start of vehicle movement will become impossible after occurrence of such vehicle slip.